注塑机螺杆表面激光Cr-Mo-B合金化层制备及工艺研究

Preparation and technology of laser chromium-molybdenum-boron alloying layer on screw surface of injection molding machine

为改善螺杆的表面性能,通过激光合金化技术在45钢表面制备Cr-Mo-B三元合金化涂层,优化合金化涂层的成分及工艺,并对最佳工艺下的Cr-Mo-B合金化涂层的组织和性能进行评价。结果表明:激光Cr-Mo-B合金化涂层最佳成分的质量比为3∶7∶90,最佳工艺参数激光功率为3.1 kW,扫描速度为54 m/h,搭接率为33.3%;其合金化区组织为Cr2B、FeB、FeMo、Fe-Cr、CrxFey,形态为柱状晶;最佳工艺下的硬度可达1 020HV0.1,磨损率为1.723×10-14m3/(N·m),磨损体积为0.047 mm3,磨损体积比基体(0.140 mm3)减少0.093 mm3。

The work aims to improve the service life of injection molding machine screw. The alloying layer of the chromiummolybdenum-boron was prepared on the surface of 45 steel by laser alloying technology,the composition and process of the alloying layer were optimized,and the microstructure and properties of the alloying layer under the optimized process were evaluated. The optimal composition ratio of laser chromium-molybdenum-boron was 3∶7∶90,and the optimal process parameters of chromium molybdenum boron alloying for 45 steel were obtained,they are laser power 3.1 kW,laser scanning speed 54 m/h,and the laser lap rate 33.3%. The alloying zone consist of Cr2 B、FeB、FeMo、Fe-Cr、CrxFeyphase. The hardness of chromiummolybdenum-boron alloy coating under the optimal process can reach up to 1 020 HV0.1,the wear rate is 1.723×10-14 m^3/(N·m),and the wear volume is 0.047 mm^3,the wear volume is 0.093 mm^3 less than that of the matrix(0.140 mm^3).